Description :The DA 100 Signature DAC runs a true 24/192kHz upsampling circuit into a steep 6th-order reconstruction filter, then a fully balanced class A current-based output stage for a claimed 120dB dynamic range. The power supply uses a 25VA toroidal transformer and the voltage regulator a 20 milliohm (10kHz) output impedance. "Voltage conversion takes place in the final stages of the circuit." The DA 100 Signature's input receiver can lock to 96kHz incoming PCM streams from a DVD player and input sensitivity on all S/PDIF sockets is 200mV.

User Review for reference :DA100 Signature USB 96/24

The Stello DA100 Signature is amended with “24/192 D/A Converter”.

On the front

there is a knob,a green LED signaling locking,a button with a LED for activating upsampling and a standby button with a corresponding indicator.

Upsampling value is indicated with a LED. If it is off – then the circuit is not active, is it green – 96/24, and is it red – 192/24.

A mechanical power switch is in the back, next to the IEC socket.

The back is really crowded. Looking from left we see a pair of analog RCA outputs, using really solid, Cardas sockets, balanced analog outputs, with Neutrik XLR sockets and five digital inputs.- AES/EBU, - RCA and TOSLINK (both S/PDIF), - USB and I2S.

All sockets – including USB – accept signals up to 24 bits and 96 kHz.

So we can clearly see, that this is NOT a 24/192 DAC. This last value tells something else – it has an upsampling circuit, which can convert the input signals to the 24/192 form, in which it is converted to analog.

When we take off the top cover, we’ll see a perfectly ordered circuit on a printed board. The signal is chosen with an integrated switch and runs to the front of the DAC for initial processing. The USB signal has a slightly longer path. We have here a modern USB receiver, using the DSP from Tenor, exactly the same as in the CD-2s Ayon Audio.

Behind the power supply, close to the front panel we have a very worked out digital section, with two splendid, mechanically and thermally protected clocks – one for the 44.1kHz frequency and its multiplicity, and one for 48kHz and derivatives. However on the input we have the AKM AK4117 IC. Interestingly, this is a 24/192 receiver, so the limit of the Stello input to 96kHz must come from different considerations. After the receiver there is an asynchronous upsampler Analog Devices AD1896, with 128 oversampling, changing every input signal to 24/96 or 24/192. As you know from the front panel, it can be bypassed. The heart of the DAC is the AKM AK4395 converter, a delta-sigma 24/192 unit, with 120dB dynamics. From there we go to the analog section, which takes over about a half of the insides. It is built using integrated circuits, with one notable exception – the output circuit, working in class A and using big transistors in push-pull setting. On the balanced output there is a single chip working as a driver for long connections.The power supply is built around a medium sized transformer with two output sections – one for the digital and one for the analog part of the DAC. It is accompanied by Nichicon capacitors. The PCB is extremely solid, with gold plated traces. Comparing it to other devices you should note the output voltage being slightly higher than the standard – 2.4V.